Rationality is a tool. Let's see how many things we can apply it to.

What is reductionism?

Reductionism <ri-duhk-shuh-niz-uhm>, n. The evil evil belief that people are made of cells. And cells are made of atoms. And atoms are made of quarks and leptons. And everything is quantum configurations in something or other.

People hate reductionism, and I think I know why. When they give the definition I’ve written above, they don’t just say that it’s the belief that people are made of cells. It says that people are just made out of cells. That ‘ just’ sounds very much like the ‘merely’ in the merely real. It’s uncomfortable to think that all of the things we treat as ontologically basic – consciousness, thought, emotions – are in fact made up of smaller, simpler things. But there’s no getting around it. Things are made of other things. Sorry!

Well, obviously things are made of other things. What we meant was that biology is never going to be explained by chemistry or physics.

Well, the word ‘explained’ is doing a lot of work there. If we came up with a complete theory of how exactly quarks worked, we could model the flight of an airplane. How could we not? Is there something about an airplane which doesn’t have to do with quarks? It looks as though there must be; our brain has a place for airplane and place for quarks, but they’re on different shelves. How can they be the same? Sorry, brain, but the world simply isn’t all that intuitive.

Now, it may be that the model of the airplane will never feel like an explanation the way lift and drag and gravity do. That’s fine. That’s just a product of how our brains work, and it will keep classical physics instructors in business even after we come up with a unified theory of everything.

Something still feels missing

I know, and that’s unfortunate. That sensation has pushed us to learn many and wonderful things, but it sometimes leads us astray. In this sense, it’s simply the case that while it’s unappealing to think that we can be explained by the mechanics of atoms, the alternative is to believe in things that aren’t made of atoms, things that just are. And that is a belief in the supernatural. Choose that path if you wish, but you’re not going to get a Theory of Everything that way.

But doesn’t that mean we don’t have free will?

Yes. Not in the way you’ve been taught to think of it. But in other ways we do. That’s for another post.

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4 thoughts on “What is reductionism?”

First, your initial definition is obviously false. People are not made of cells. They are made of cells, the particular arrangement those cells are in, fluids and other things between and inside of cells, and an environment (including various elements, radiation of various sorts, etc.) that is changing and being changed by those cells. It’s not at all obvious to me that you could _completely_ describe a person without a description of the entire observable universe. You can probably get a good first approximation just by looking at cells, but that’s engineering, not philosophy.

>> If we came up with a complete theory of how exactly quarks worked, we could model the flight of an airplane. How could we not? Is there something about an airplane which doesn’t have to do with quarks?

You are invalidly importing your existing higher-level knowledge of what an airplane is, here. The “part of the airplane that doesn’t have to do with quarks” is the function of the airplane in human society, and the resulting scientific attention it receives. A purely quark’d description of the universe would not include anything with a quarky “airplane” label.

Maybe we’ll eventually have a ToE. (I don’t think there’s any reason to think that’s guaranteed, but it’s possible.) But a) We don’t have one yet. b) If we did have one, we couldn’t calculate anything complicated with it, given computer limitations. c) It would require human interpretation, including the use of non-ToE concepts, to tell us anything we actually care about.

Also, perhaps more basically: I’m curious what you argument is for the claim that “things are made of other things”. You seem to take it as obvious and given, but isn’t that just begging the question? Of course if reductionism is true, it’s true.